(1) Field of the Invention
The present invention relates to a cooling microcircuit for use in turbine engine components, such as turbine blades, that has a plurality of vortex generators within the legs through which a cooling fluid flows to improve cooling effectiveness.
(2) Prior Art
A typical gas turbine engine arrangement includes at plurality of high pressure turbine blades. In general, cooling flow passes through these blades by means of internal cooling channels that are turbulated with trip strips for enhancing heat transfer inside the blade. The cooling effectiveness of these blades is around 0.50 with a convective efficiency of around 0.40. It should be noted that cooling effectiveness is a dimensionless ratio of metal temperature ranging from zero to unity as the minimum and maximum values. The convective efficiency is also a dimensionless ratio and denotes the ability for heat pick-up by the coolant, with zero and unity denoting no heat pick-up and maximum heat pick-up respectively. The higher these two dimensionless parameters become, the lower the parasitic coolant flow required to cool the high-pressure blade. In other words, if the relative gas peak temperature increases from 2500 degrees Fahrenheit to 2850 degrees Fahrenheit, the blade cooling flow should not increase and if possible, even decrease for turbine efficiency improvements. That objective is extremely difficult to achieve with current cooling technology. In general, for such an increase in gas temperature, the cooling flow would have to increase more than 5% of the engine core flow.